This invention relates to an energy absorbing support system for a vehicle steering mechanism that includes a steering wheel and a rotary steering shaft extending from the steering wheel.
Mechanisms have been devised for allowing vehicle steering wheels to collapse in the event that the driver of the vehicle should forcibly impact the steering wheel during a vehicle crash incident e.g. a front end collision. Such mechanisms are conventionally formed out of stamped metal components suitably welded, or otherwise connected together, to form a deformable support system for the steering shaft and steering wheel.
One problem with such conventional mechanisms is that the stamped components can deflect, or deform, under normal operating loads. In a crash situation the mechanisms can act as a stiff spring so as to delay or prevent collapse of the steering wheel, with the possibility of a momentary oscillating condition tending to prolong human injury. Conventional collapse systems are somewhat unpredictable in crash situations.
The present invention relates to an energy-absorbing support system for a vehicle steering mechanism, wherein a principal component of the mechanism is formed as a one-piece rigid metal die casting. This rigid metal die casting acts as a support for the vehicle steering shaft and vehicle steering wheel during normal vehicle operations. In a crash situation, the collapse mechanism shears at a predictable shock loading, with minimal time delay in the collapse action.
The rigid die casting has a releasable attachment to an overhead mounting member, via plural shearable fastening devices. Also, the rigid metal die casting has energy-absorbing devices connected to the overhead mounting member, whereby the velocity of the steering system is controlled during the collapsing motion.
Further features of the invention will become apparent from the attached drawing and description of an illustrative embodiment of the invention.